We're suddenly getting a 'Something went wrong. Refresh the page to try again' error when anybody tries to access a published timeline view.

It has previously been accessible with no issue. I tried refreshing a few times and then got a 'We can't load ideas data from the server' error:

I can see the timeline view within the project without an issue, it's just the link for the published view that gets this error. Interestingly, I can still see the text in the 'About' - it's just the timeline that doesn't show.
Anyone else get this error? I found an old question with the same issue from a few years back but there didn't seem to be a definitive answer.